Two-cycle engine regulation



Feb. 19, 1935. ROTTER TWO-CYCLE ENGINE REGULATION Filed Dec. 5, 1932 MW fi/ INVENTOR. M M

Patented Feb. 19, 1935 UNITED STATES PATENT OFFICE Two-cYcLE ENGINE REGULATION Max Rotter, Milwaukee, Wis., assignor to Busch- Sulzer Bros'.-Diesel Engine Company, St. Louis, Mo., a corporation of Missouri Application December 5, 1932, serial No. 645,698

2 Claims. (01. 123-65) 5 being to obtain special efficiency for the scavenging and charging or supercharging functions under all loads, from light to heavy, by the use of a simple air source at a single pressure.

The accompanying drawing which is purely diagrammatic will suffice to exemplify the principle of the invention. a

The numeral 1 identifies the air receiver usual in these engines and will be understood to be merely a horizontal air conduit, which may be common to all the cylinders in a multi-cylinder engine and which is connected to an air blower, not shown, driven directly by the engine or electrically as preferred. A single cylinder is indicated in the diagram. Air from this receiver may flow into the engine cylinder through an upper air admission port 2, or tier of such ports and also through a lower port 3 or tier of such ports. The exhaust is through a port 3 or tier of such ports. The piston on its downward stroke first opens the upper air port, then the exhaust port and lastly the lower air port and on its upstroke closes the exhaust before it closes the, upper air port. The upper air port is provided with a set of overlapping shutters 5 which represent or are the equivalent of a check valve to permit flow into the cylinder but prevent flow from the cylinder into the receiver. For the operation and regulation of the engine according to this invention this check-valve control of the upper air port is an important factor.

According to this invention the air flow to the lower air port is subject to variable control in accordance with the variation of the load on the engine for which purpose it is provided with a damper, throttle or the like marked 6 connected by appropriate connections 7 with the engine governor 8, in such Way that the throttle is open (dotted line position) when the load is light and closed (full line position) when the load is heavy. A manual control is indicatedat 9 in the diagram.

This arrangement produces the following efiects: The load being light and no supercharging being needed, the throttle 6 is open and both air ports operate as though no throttle were present; that is to say on the pistons down-stroke both air ports discharge into the cylinder as soon as On the up-stroke both ports continue to discharge air into the cylinder until the lower air port is covered; thereafter the upper air port only con-- tinues in action until the'exhaust port is closed and until pressure balance occurs between receiver and cylinder.

When, however, the throttle 6 is closed, as at a heavy load, the whole air admission occursby way of the upper air port with the result that the pressure in the receiver is then increased relatively to the condition first described and accordingly after the ascending piston'has closed the exhaust port, theflow through such upper port continues until balance at higher pressure has been established, thereby putting a greater weight of air (supercharging) into the cylinder for compressionbythe piston, consonant with a largerdelivery of fuel by the injector 10 at the heavy load. Thorough scavenging occurs when both ports are allowed to function, that being specially desirable under lighter loads, and adequate scavenging and also supercharging are effected for heavier loads (lower speeds) by the upper port acting alone under the higher air pressure, while for intermediate loads it will be apparent that intermediate degrees of the described effect are produced according to the intermediate positions of the governor, the rate of throttling of the lower port with reference to the engine speed being set or adjusted in general proportion to the rate of fuel increase. By the means described the combustion aircharge is increased as and when needed without unduly increasing the work expendedin compressing the air for the receiver when reduced charging suffices.

I claim:

1. In a two-cycle injection engine having upper and lower air admissionports and an exhaust port all controlled by the piston, an air receiver common to both air ports to supply the same with air under moderate pressure for scavenging and charging, means responsive to load variations, a check valve preventing reverse flow through the upper air port and a throttle for the lower air port controlled by said load responsive means.

2. In a two-cycle injection engine having upper and lower air admission ports and an exhaust port all controlled by the piston, an engine governor driven by theengine, an air receiver common to both said air ports, a check valve for the upper port and a throttle means for the lower port operated in accordance with changes of position of said governor.

. MAX RO'I'I'ER. 

